[PATCH v7 10/25] ACPI / APEI: Tell firmware the estatus queue consumed the records

James Morse
2018-12-03T18:34:32Z

ACPI has a GHESv2 which is used on hardware reduced platforms to
explicitly acknowledge that the memory for CPER records has been
consumed. This lets an external agent know it can re-use this
memory for something else.

Previously notify_nmi and the estatus queue didn't do this as
they were never used on hardware reduced platforms. Once we move
notify_sea over to use the estatus queue, it may become necessary.

Add the call. This is safe for use in NMI context as the
read_ack_register is pre-mapped by ghes_new() before the
ghes can be added to an RCU list, and then found by the
notification handler.

Signed-off-by: James Morse <james.morse@arm.com>
---
drivers/acpi/apei/ghes.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
index 366dbdd41ef3..15d94373ba72 100644
--- a/drivers/acpi/apei/ghes.c
+++ b/drivers/acpi/apei/ghes.c
@@ -926,6 +926,10 @@ static int _in_nmi_notify_one(struct ghes *ghes)
__process_error(ghes);
ghes_clear_estatus(ghes, buf_paddr);

+ if (is_hest_type_generic_v2(ghes) && ghes_ack_error(ghes->generic_v2))
+ pr_warn_ratelimited(FW_WARN GHES_PFX
+ "Failed to ack error status block!\n");
+
return 0;
}

--
2.19.2